Eye Conditions

What is Astigmatism?

Astigmatism

Astigmatism occurs when the cornea is shaped more like an oblong football than a spherical baseball. An astigmatic cornea has a steeper curve and a flatter one, causing light rays to focus on two points in the back of your eye, rather than on just one, causing blurred vision at all distances.

Until now, people with astigmatism have had only two choices for contact lens wear: “hard” or soft toric contact lenses. “Hard” lenses offer crisp, clear vision but are often irritating and uncomfortable. Soft toric lenses have a reputation for comfort but sometimes rotate, causing inconsistent vision.

Soft Toric Contact Lenses

Most people with astigmatism cannot wear standard soft contact lenses, because standard, or spherical, soft lenses have the same power all around the lens. Toric lenses are made from the same material as soft contacts but are designed differently.

Toric lenses have two powers in them, one for astigmatism, the other for either nearsightedness or farsightedness. To correct your vision, the two powers need to remain stable so toric lenses can’t rotate on your eye. To do this, they are designed so that the bottom portion of the lens is weighted slightly so the lens stays fairly stable when you blink or shift your gaze. However, most toric lens wearers still experience some lens rotation on blink or gaze shift, known as “toric lens rotation,” which results in temporarily blurred vision. This unstable vision can occur anytime and is often more noticeable in lower levels of illumination, such as driving at night.

“Hard” or Gas Permeable (GP) Lenses

With “hard” lenses, or GPs, the lenses’ rigidity can help mask a need for an astigmatic correction: when GP lenses are placed on the astigmatic cornea the space between the back of the GP lens and the surface of the cornea is filled up by tears. This layer of tears functions to correct the astigmatism, so a GP contact lens needs to have only one power to correct any near or far sightedness.

The downside to GP lenses is their less-than-optimal comfort due to the stiffness of the lens material. Rigid lens wearers also experience the irritation of debris collecting under the lens, and may dislodge during activity.

What is Farsightedness?

If you are farsighted (hyperopic) you have difficulty seeing objects close-up, which is the result of light rays focusing behind the retina rather than on it.

If you’re farsighted, your prescription begins with a plus number. The higher the numeral, the stronger your lenses will be. Farsightedness can be corrected with glasses or contact lenses.

“Hard” (rigid gas permeable) lenses are best for providing crisp, clear vision, especially for people with higher amounts of hyperopia. However, hard lenses are often irritating and uncomfortable. Rigid lens wearers also experience the irritation of debris collecting under the lens, and rigid lenses move when you blink and may dislodge during activity.

Soft lenses are the most comfortable to wear, but often provided soft, fuzzy vision. For people with higher amounts of hyperopia, soft contact lenses may not provide enough correction to deliver good vision.

Ready to optimize your contact lens experience?

No matter what type of contact lenses you currently use, there’s a good chance you’re compromising on either clarity or comfort. Now a technological breakthrough makes having to choose a thing of the past.

What is Nearsightedness?

If you are nearsighted (myopic) you have difficulty seeing objects that are far away which is the result of light rays focus in front of the retina, rather than on it.

If you’re nearsighted, your prescription is a negative number. The higher the numeral, the stronger your lenses will be. Nearsightedness can be corrected with glasses or contact lenses.

“Hard” (rigid gas permeable) lenses are best for providing crisp, clear vision, especially for people with higher amounts of myopia. However, hard lenses are often irritating and uncomfortable. Rigid lens wearers also experience the irritation of debris collecting under the lens, and rigid lenses move when you blink and may dislodge during activity.

Soft lenses are the most comfortable to wear, but often provided soft, fuzzy vision. For people with higher amounts of myopia, soft contact lenses may not provide enough correction to deliver good vision.

Ready to optimize your contact lens experience?

No matter what type of contact lenses you currently use, there’s a good chance you’re compromising on either clarity or comfort. Now a technological breakthrough makes having to choose a thing of the past.

Vision Over 40

What is Presbyopia?

Over 40 (presbyopia)

Presbyopia is a natural part of the aging process and affects everyone over forty years of age. People usually notice the condition around age 45, when they realize that they need to hold reading materials further away in order to focus on them.

The process by which the eye increases its power to see things clearly close up is called accommodation. Accommodation can be described as the “auto focus” feature similar to that on a camera. Just as a camera lens needs to be moved back and forth to focus clearly on the object being photographed, an eye adjusts its power to focus on things up close or in the distance.

As presbyopia starts to develop, the eye power becomes a “fixed-focus” losing its ability to “auto-focus” on things at different distances, providing clear vision only at a particular distance. If the vision is corrected for distance, seeing things close up becomes a challenge with the distance vision correction. The reverse also holds true. When the vision for close up distance for people with presbyopia is corrected, distance vision will be blurred.

The unique Duette® Progressive hybrid design eliminates the instability and soft optics issues of other multifocal contact lenses. You’ll never have to juggle multiple vision solutions – glasses and bifocals, or bifocals and contacts – again. The precision rigid gas permeable center and the soft contact lens skirt of the new revolutionary Duette Progressive hybrid contact lens provides clear, crisp, consistent vision at distance and close up. The irregularities of the front surface of the eye that are typically transferred to the front surface of a soft contact lens are neutralized by the tear film between the eye and the rigid gas permeable center. All nearsightedness, farsightedness and astigmatism are corrected by the distance power, while the crisp optics of the close up power provides simultaneous computer and reading vision with minimal interference with distance vision. With the Duette Progressive contact lens, now you can experience ageless vision near and far.

If you are experiencing blurry vision while reading because of presbyopia and want to experience ageless vision near and far and clear, crisp vision when looking at things close up or at a distance, ask your eye care practitioner about the Duette Progressive lens.To learn more about the Duette Progressive lens, click here.

Why do I need reading glasses when I’ve never had trouble seeing up close before?

Like everyone else over the age of 40, you’re dealing with a condition called presbyopia. Presbyopia is an age-related loss of near focusing ability that is caused by a thickening and loss of flexibility of the lens of the eye. When the lens loses its flexibility, it’s much harder to focus on objects at varying distances. The result is blurred near vision.

Are there any alternatives to reading glasses?

Yes, you have several options for improving your near vision without reading glasses.

Multifocal contact lenses are contacts with multiple powers in them to help you see up close, far away and everywhere in between. Multifocal contact lenses may be made of hard, soft or hybrid materials.

Monovision is another contact lens option that corrects one eye for distance and one eye for near. The brain learns to favor one eye over the other for different tasks.

Progressive glasses are spectacle lenses with multiple powers in them to help you see at all distances.

Irregular Cornea Eye Conditions

What is Keratoconus?

Keratoconus is a degenerative eye disease that causes the cornea to thin and bulge, creating a cone-like irregular shape. Because the cornea is responsible for refracting most of the light that comes into the eye, any irregularity of the cornea can result in significant visual impairment. Keratoconus most often appears in a person’s late teenage years; although it has been diagnosed in people in their forties and fifties. The eye disease has been estimated to occur in roughly one out of every 2,000 people in the general population. No significant geographical, gender, ethnic, or social pattern has been established, and keratoconus occurs in all parts of the world.

What causes keratoconus?

The exact cause of keratoconus is not known; however, there are many theories on what may trigger this disease. It is important to note that no one theory provides a complete explanation, and it is likely that keratoconus is caused by a combination of things. It is believed that genetics, the environment, and the endocrine system all play a role in keratoconus:

Genetics: Although keratoconus sometimes affects more than one member of the same family, current research indicates that there is less than a one in ten chance that a blood relative of a keratoconic patient will have keratoconus.

Environmental Factors: Keratoconus may also be associated with overexposure to ultraviolet rays from the sun, excessive eye rubbing, a history of poorly fit contact lenses and chronic eye irritation.

Endocrine System: Another hypothesis is that the endocrine system (which dictates the release of hormones) may be involved, since keratoconus is often first diagnosed in adolescence

What is a Corneal Ectasia?

Ectasia is defined as the expansion of body tissue, in this case the cornea which is the clear dome covering the colored part of the eye. The cornea’s primary responsibility is to focus light onto the retina to create clear, sharp vision. When the cornea thins, or becomes ectactic, it distorts the vision causing blur, multiple images, glare, haloes, dry eyes, light sensitivity and other undesirable visual phenomena.

What is Pellucid Marginal Degeneration (PMD)?

PMD is a degenerative corneal condition, often confused with keratoconus, that is the second most common noninflammatory corneal thinning disorder behind keratoconus. It is typically characterized by a clear, bilateral thinning (ectasia) in the inferior and peripheral region of the cornea, although some cases affect only one eye. PMD typically presents in the second to fifth decade of life. The cause of the disease remains unclear.

What is Corneal Crosslinking?

Corneal Collagen Crosslinking or CXL, is a treatment that works by strengthening corneal tissue to halt the bulging of the eye’s surface. The goal of this treatment is to stop the progression of keratoconus, and thereby prevent further deterioration in vision and the need for corneal transplantation. While this doesn’t correct or reverse keratoconus, it has been shown to significantly strengthen the cornea to keep it from getting worse.

The treatment is currently in F.D.A. clinical trials but is available in the European Union and many other countries. A patient with keratoconus who needed to wear contact lenses prior to CXL would still need to wear them after the treatment, but should experience less need to change the lens prescription.

NOTE: SynergEyes is not involved with the research and development nor commercialization of corneal crosslinking.